Electrospun Ti<sub>3</sub>C<sub>2</sub> MXene Fiber‐Decorated Interlayer for Synchronous Sulfur Activation and Lithium Stabilization
Bo Zhao, Lixian Song, Zhijuan Zou, Zhu Xiong, Yunfeng Zhang, Qin Yang, Zixiong Shi, Yaping Zhang, Yingze Song
Abstract
Abstract Concurrent regulation of sulfur redox kinetics and lithium deposition homogeneity is a key prerequisite for achieving high‐performance lithium–sulfur (Li–S) batteries. To this end, rational design of dual‐functional interlayers is recognized as a feasible yet promising approach. Herein, few‐layered Ti 3 C 2 MXene flakes are uniformly decorated into the porous carbon nanofiber film via a straightforward electrostatic spinning technique, wherein the Ti 3 C 2 MXene content is fine‐tuned to maximum sulfur utilization and stabilize lithium anode. For one thing, it is revealed by synchrotron radiation X‐ray three‐dimensional nano‐computed tomography that Ti 3 C 2 MXene‐decorated fiber can expedite polysulfide conversion and induce favorable Li 2 S nucleation. For another, small‐angle neutron scattering evidence substantiates that abundant lithiophilic sites are conducive to homogenizing Li‐ion flux and promoting lithium deposition during cycling procedure. As a consequence, Li–S batteries maintain a stable operation at 2.0 C over 1000 cycles with a low‐capacity degeneration rate of 0.057% per cycle, accompanied by a superior areal capacity of 7.5 mAh cm −2 when the sulfur loading is increased to 9.5 mg cm −2 . More encouragingly, the as‐assembled multi‐layer Li–S pouch cell deliver an impressive cell energy density of 342.3 Wh kg −1 with smooth cyclic operation.